Scoop out the avocado into a bowl and mash with a fork. Add the lemon juice and salt and pepper to taste. Combine and set aside .
Poach your eggs until your desired doneness. I just lift with a slotted spoon and feel for firmness. Remove and drain on a paper towel. If you prefer cook your eggs sunny side up or how you prefer.
Heat your tostados under the broiler or in your oven. Spread each with the avocado. Top with your eggs. Add a little salt and pepper to your eggs and red pepper flakes if you like. Serve with your favorite salsa if you like.